移动手持环境下触摸式目标选择技术对比

目的触摸输入方式存在"肥手指"、目标遮挡和肢体疲劳现象,会降低触摸输入的精确度。本文旨在探索在移动式触摸设备上,利用设备固有特性来解决小目标选择困难与触摸输入精确度低的具体策略,并对具体的策略进行对比。方法结合手机等移动式触摸设备所支持的倾斜和运动加速度识别功能,针对手机和平板电脑等移动式触摸输入设备,实证地考察了直接触摸法、平移放大法、倾斜法和吸引法等4种不同的目标选择技术的性能、特点和适用场景。结果通过目标选择实验对4种技术进行了对比,直接触摸法、平移放大法、倾斜法、吸引法的平均目标选择时间,错误率和主观评价分别为(86.06 ms,62.28%,1.95),(1 327.99 ms,6.93%,3.87),(1 666.11 ms,7.63%,3.46)和(1 260.34 ms,6.38%,3.74)。结论 3种改进的目标选择技术呈现出了比直接触摸法更优秀的目标选择能力。     

AttachedShock: Design of a crossing-based target selection technique on augmented reality devices and its implications

The prevalence of touch devices in daily lives offers increasing opportunities for users to navigate the real world. However, as users move, on-screen targets move unpredictably, and eventually disappear from the screen in mobile navigation scenarios. The changing target movement pattern creates difficulties in selecting targets in time before targets escape from the screen. This study proposes a novel selecting technique, AttachedShock, for easing target selection tasks on augmented reality devices by crossing a naturally expanding wave pattern attached to targets. We evaluated the effectiveness of our technique by conducting three sets of comparative studies on measuring the performance of four techniques under various mobile navigation scenarios, i.e., various combinations of the identified factors. The results indicate that the proposed technique assists users in selecting moving targets to improve the error rate substantially, by a minimum of 76.51%, 61.75%, and 72.77% in Experiment-I, -II, and -III relative to state-of-the-art techniques, and incurs acceptable distractions to users, compared to other techniques.     

Eyes-free interaction with free-hand gestures and auditory menus

Auditory interfaces can overcome visual interfaces when a primary task, such as driving, competes for the attention of a user controlling a device, such as radio. In emerging interfaces enabled by camera tracking, auditory displays may also provide viable alternatives to visual displays. This paper presents a user study of interoperable auditory and visual menus, in which control gestures remain the same in the visual and the auditory domain. Tested control methods included a novel free-hand gesture interaction with camera-based tracking, and touch screen interaction with a tablet. The task of the participants was to select numbers from a visual or an auditory menu including a circular layout and a numeric keypad layout. Results show, that even with participant's full attention to the task, the performance and accuracy of the auditory interface are the same or even slightly better than the visual when controlled with free-hand gestures. The auditory menu was measured to be slower in touch screen interaction, but questionnaire revealed that over half of the participants felt that the circular auditory menu was faster than the visual menu. Furthermore, visual and auditory feedback in touch screen interaction with numeric layout was measured fastest, touch screen with circular menu second fastest, and the free-hand gesture interface was slowest. The results suggest that auditory menus can potentially provide a fast and desirable interface to control devices with free-hand gestures.     

A graphical-based password keystroke dynamic authentication system for touch screen handheld mobile devices

Since touch screen handheld mobile devices have become widely used, people are able to access various data and information anywhere and anytime. Most user authentication methods for these mobile devices use PIN-based (Personal Identification Number) authentication, since they do not employ a standard QWERTY keyboard for conveniently entering text-based passwords. However, PINs provide a small password space size, which is vulnerable to attacks. Many studies have employed the KDA (Keystroke Dynamic-based Authentication) system, which is based on keystroke time features to enhance the security of PIN-based authentication. Unfortunately, unlike the text-based password KDA systems in QWERTY keyboards, different keypad sizes or layouts of mobile devices affect the PIN-based KDA system utility. This paper proposes a new graphical-based password KDA system for touch screen handheld mobile devices. The graphical password enlarges the password space size and promotes the KDA utility in touch screen handheld mobile devices. In addition, this paper explores a pressure feature, which is easy to use in touch screen handheld mobile devices, and applies it in the proposed system. The experiment results show: (1) EER is 12.2% in the graphical-based password KDA proposed system. Compared with related schemes in mobile devices, this effectively promotes KDA system utility; (2) EER is reduced to 6.9% when the pressure feature is used in the proposed system. The accuracy of authenticating keystroke time and pressure features is not affected by inconsistent keypads since the graphical passwords are entered via an identical size (50 mm × 60 mm) human–computer interface for satisfying the lowest touch screen size and a GUI of this size is displayed on all mobile devices.     

Using large tables on small display devices

The next evolutionary step in wireless Internet information management is to provide support for tasks, which may be collaborative and may include multiple target devices, from desktop to handheld. This means that the information architecture supports the processes of the task, recognizes group interaction, and lets users migrate seamlessly among internet-compatible devices without losing the thread of the session. If users are free to migrate amongst devices during the course of a session then intelligent transformation of data is required to exploit the screen size and input characteristics of the target appliance with minimal loss of task effectiveness.In this paper we first review general characteristics related to the performance of users on small screens and then examine the navigation of full tables on small screens for users in multi-device scenarios. We examine the methodologies available for access to full tables in environments where the full table cannot be viewed in its entirety. In particular, we examine the situation where users are collaborating across platform and referring to the same table of data. We ask three basic questions: Does screen size affect the performance of table lookup tasks? Does a search function improve performance of table lookup based tasks on reduced screen sizes? Does including context information improve the performance of table lookup based tasks on reduced screen sizes? The answers to these questions are important as individual and intuitive responses are used by the designers of small screen interfaces for use with large tables of data. We report on the results of a user study that examines factors that may affect the use of large tables on small display devices. The use of large tables on small devices in their native state becomes important in at least two circumstances. First, when collaboration involves two or more users sharing a view of data when the individual screen sizes are different. Second, when the exact table structure replication may be critical as a user moves quickly from a larger to a smaller screen or back again mid-task. Performance is measured by both effectiveness, correctness of result, and efficiency, effort to reach a result.     

Stroke++: A new Chinese input method for touch screen mobile phones

Over the past few decades, users have been feeling clumsy inputting Chinese on mobile devices, partly because the layout of the keyboard/keypad is originally designed for inputting Latin alphabets. To improve this user experience, we propose Stroke++, a novel Chinese input method for touch screen mobile devices. More specifically, Stroke++ provides efficient keypad layout, a friendly user interface and a intelligent character/phrase candidate set generation algorithms. Stroke++ splits a Chinese character into multiple radicals. By leveraging hieroglyphic properties of Chinese characters, our method requires users to only input a subset of the radicals to identify the target character, making it much faster and easier to input Chinese on mobile phones. Our user study results show that Stroke++ outperforms most major Chinese input methods on mobile devices, including Stroke, Pinyin and Hand Writing Recognition (HWR), in terms of the input efficiency and usability. Moreover, we also demonstrate that Stroke++ offers a low entry barrier for Chinese-input novices.     

Improving web search on small screen devices

Small handheld devices—mobile phones, Pocket PCs etc.—are increasingly being used to access the web. Search engines are the most used web services and are an important factor of user support. Search engine providers have begun to offer their services on the small screen. This paper presents a detailed evaluation of the how easy to use such services are in these new contexts. An experiment was carried out to compare users' abilities to complete search tasks using a mobile phone-sized, handheld computer-sized and conventional, desktop interface to the full Google™ index. With all three interfaces, when users succeed in completing a task, they do so quickly (within 2–3 min) and using few interactions with the search engine. When they fail, though, they fail badly. The paper examines the causes of failures in small screen searching and proposes guidelines for improving these interfaces. In addition, we present and discuss novel interaction schemes that put these guidelines into practice.     

Improving Web interaction on small displays

Soon many people will retrieve information from the Web using handheld, palmsized or even smaller computers. Although these computers have dramatically increased in sophistication, their display size is — and will remain — much smaller than their conventional, desktop counterparts. Currently, browsers for these devices present Web pages without taking account of the very different display capabilities. As part of a collaborative project with Reuters, we carried out a study into the usability impact of small displays for retrieval tasks. Users of the small screen were 50% less effective in completing tasks than the large screen subjects. Small screen users used a very substantial number of scroll activities in attempting to complete the tasks. Our study also provided us with interesting insights into the shifts in approach users seem to make when using a small screen device for retrieval. These results suggest that the metaphors useful in a full screen desktop environment are not the most appropriate for the new devices. Design guidelines are discussed, here, proposing directed access methods for effective small screen interaction. In our ongoing work, we are developing such `meta-interfaces' which will sit between the small screen user and the `conventional' Web page.     

Investigation of Icon Design and Touchable Area for Effective Smart Phone Controls

As the full‐touch screen is being implemented in more smart phones, controllability of touch icons need to be considered. Previous research focused on recommendations for absolute key size. However, the size of tactual input on touch interface is not precisely equal to the icon size. This study aims to determine the suitable touchable area to improve touch accuracy. In addition, there was an investigation into the effect of layout (3 × 4, 4 × 5, 5 × 6, and 6 × 8) and icon ratio (0.5, 0.7, and 0.9). To achieve these goals, 40 participants performed a set of serial tasks on the smart phone. Results revealed that the layout and icon ratio were statistically significant on the user response: input offset, hit rate, task completion time, and preference. The 3 × 4 and 4 × 5 layouts were shown to have better performance. The icon ratio of 0.9 was shown to have greater preference. Furthermore, the hit rate (proportion of correct input) of touchable area was estimated through the bivariate normal distribution of input offset. The hit rate could vary, depending on the size of touchable area, which is a rectangle that yields a specific hit rate. A derivation procedure of the touchable area was proposed to guarantee the desirable hit rate. Meanwhile, the locations of the central region indicated a pattern of vertical touch and showed better performance. The users felt more difficulty when approaching the edge of the frame. The results of this study could be used in the design of touch interfaces for mobile devices.     

基于目标跟踪的红外触摸屏优化算法

针对现有红外触摸屏多点识别时识别错乱和画图时轨迹毛刺严重等问题,在原有识别算法的基础上,加入了卡尔曼滤波与跟踪门算法结合的目标跟踪算法处理,提出一种新型红外触摸屏优化算法。该算法通过数据关联中的跟踪门逻辑,将量测值与已有的目标轨迹进行逻辑判断,选择正确的触点信息,剔除伪触点的信息,实现轨迹关联和目标跟踪。同时在红外触摸屏上建立触点的运动模型上,通过卡尔曼滤波实现轨迹的平滑和一定程度上的轨迹预测。在红外触摸屏上的测试表明,与原有的识别算法相比,优化算法增加了约3 μs单点识别时间,但是提高了轨迹在拐角处的平滑度,减少了拐角处约60%的毛刺。优化算法有效地修正了红外触摸屏原有的不足,能实现多触点时的轨迹关联和提高轨迹的平滑程度,能提高红外触摸屏绘图时的实际使用效果。     

Comparison of a touch-sensitive VDU and computer-aided keypad for plant control

The technology of touch screens is discussed with emphasis on the development of appropriate software and human factors. A touch screen was compared with an intelligent keypad in an experiment in which CEGB personnel controlled simulated plant. Users preferred the touch screen in normal conditions and particularly for emergency working. Also, a statistically significant improvement in plant controllability was recorded when the touch screen was used in place of the keypad. Touch screens are seen to possess many advantages over conventional man-machine interfaces. Their use is shown to be appropriate in applications suchas alarm analysis, data and mimic selection and interactive graphics as well as for controlling plant.     

基于微型投影仪的人机交互系统

传统操作的鼠标模式使得操作者被限制在屏幕面前一定距离且动作受到拘束,破坏了体验感。本论文进行的是一种可将任意界面经过投影变成一块虚拟触摸屏的光触感受的探索。实现了一种概念性的新型界面交互体验。用户能够利用光触控技术,像在其他手持设备上那样方便的与信息浏览内容进行交互。将来主要应用领域为公共社交场所中娱乐交互,智能家居以及展览展示场所如图书馆,博物馆,文化馆等。     

Enhancing typing performance of older adults on tablets

Touch screen interfaces are increasingly more popular. However, they lack haptic feedback, making it harder to perform certain tasks, such as text entry, where users have to constantly select one of many small targets. This problem particularly affects older users, whose deteriorating physical and cognitive conditions, combined with their unfamiliarity with technology, can discourage them from using touch devices. The goal of this work was to thoroughly understand older adults touch typing behavior, in order to develop text-entry solutions more appropriate to their needs, which will enhance their typing performance. On a first phase, a baseline QWERTY keyboard and five different variants were developed that mostly used a text prediction algorithm to suggest the most probable keys or words. These keyboards were evaluated on a baseline study with 20 younger adults in order to find the most promising ones, which were then used in a study with 20 older adults. The older adults study revealed more about their typing behavior and therefore created four new variants to be used in a simulation study. Results show that visual changes should be kept to a minimum; touch points should be shifted upward and to the opposite side of the hand used to type; single touch keyboards perform better than multi-touch; and omitting keys below a certain time threshold minimizes accidental insertions.     

Controlling a Smartphone Using Gaze Gestures as the Input Mechanism

The emergence of small handheld devices such as tablets and smartphones, often with touch sensitive surfaces as their only input modality, has spurred a growing interest in the subject of gestures for human–computer interaction (HCI). It has been proven before that eye movements can be consciously controlled by humans to the extent of performing sequences of predefined movement patterns, or “gaze gestures” that can be used for HCI purposes in desktop computers. Gaze gestures can be tracked noninvasively using a video-based eye-tracking system. We propose here that gaze gestures can also be an effective input paradigm to interact with handheld electronic devices. We show through a pilot user study how gaze gestures can be used to interact with a smartphone, how they are easily assimilated by potential users, and how the Needleman-Wunsch algorithm can effectively discriminate intentional gaze gestures from otherwise typical gaze activity performed during standard interaction with a small smartphone screen. Hence, reliable gaze–smartphone interaction is possible with accuracy rates, depending on the modality of gaze gestures being used (with or without dwell), higher than 80 to 90%, negligible false positive rates, and completion speeds lower than 1 to 1.5 s per gesture. These encouraging results and the low-cost eye-tracking equipment used suggest the possibilities of this new HCI modality for the field of interaction with small-screen handheld devices.     

Real world teleconferencing

We've been exploring how augmented reality (AR) technology can create fundamentally new forms of remote collaboration for mobile devices. AR involves the overlay of virtual graphics and audio on reality. Typically, the user views the world through a handheld or head-mounted display (HMD) that's either see-through or overlays graphics on video of the surrounding environment. Unlike other computer interfaces that draw users away from the real world and onto the screen, AR interfaces enhance the real world experience. For example, with this technology doctors could see virtual ultrasound information superimposed on a patient's body.     

The effects of graphic metaphor,gesture interaction,and form factor on e‐book performances and preferences

Reading e‐books on touch‐based mobile devices such as smartphones and tablet personal computer (PCs) are increasing. We conducted a comparative study on the usability of e‐books provided on smartphones and tablet PCs, which are typical touch‐based mobile devices. An experiment was carried out to see the effects of graphic metaphor and gesture interaction. This study evaluated reading speed, readability, similarity, and satisfaction for 16 combinations of e‐book interfaces (two Metaphor levels × four Display size and Screen modes × two Gesture levels). Overall, performance and subjective ratings showed better results on tablet PCs with larger fonts on a larger screen than on smartphones with smaller fonts on smaller screens. In the smartphone‐landscape mode, the effect of turning a page is a factor that hinders the speed of user reading. In contrast, the users’ readability, similarity, and satisfaction were higher when the page‐turning effect was provided. It showed faster reading speeds when a flicking interaction is provided on tablet PCs. From the standpoint of readability, the portrait mode was better on smartphones. Also, the tablet PC‐portrait mode was the most satisfactory.     

Dual-Finger 3D Interaction Techniques for mobile devices

Three-dimensional capabilities on mobile devices are increasing, and the interactivity is becoming a key feature of these tools. It is expected that users will actively engage with the 3D content, instead of being passive consumers. Because touch-screens provide a direct means of interaction with 3D content by directly touching and manipulating 3D graphical elements, touch-based interaction is a natural and appealing style of input for 3D applications. However, developing 3D interaction techniques for handheld devices using touch-screens is not a straightforward task. One issue is that when interacting with 3D objects, users occlude the object with their fingers. Furthermore, because the user’s finger covers a large area of the screen, the smallest size of the object users can touch is limited. In this paper, we first inspect existing 3D interaction techniques based on their performance with handheld devices. Then, we present a set of precise Dual-Finger 3D Interaction Techniques for a small display. Finally, we present the results of an experimental study, where we evaluate the usability, performance, and error rate of the proposed and existing 3D interaction techniques.     

Distance estimation of near‐field visual objects in stereoscopic displays

Stereoscopic displays have a promising future because of recent advancements and popularity of handheld devices and maturing head mounted displays. Gesture interaction such as pointing, selection, pinching, and manipulation are now possible in the current virtual environments, where accurate distance judgment is required. In this paper, we address the perception of exocentric distance in stereoscopic displays under two target orientations: horizontal and vertical. Three parallax conditions (on screen, 5 cm from screen, and 10 cm from screen) were considered, where the screen was fixed at a distance of 100 cm from the observer. Four levels of center‐to‐center distance between 10 and 50 cm were employed. The perceptual matching task revealed underestimation in all conditions. The overall judgment of exocentric distance was only about 80% of the actual. We also found a main effect of distance and interaction between layout and distance to be significant. The two important findings of this study are that underestimation of exocentric distance increases as the separation between virtual targets increases and that in vertical orientation, accuracy increases with closer targets. However, the main effects of layout and parallax on accuracy of judgment were not significant. Engineering implications of the results are also discussed in this paper.     

Advances in interactive display technologies

How we interface and interact with computing, communications, and entertainment devices is going through revolutionary changes, with natural user inputs based on touch, gesture, and voice replacing or augmenting the use of traditional user interfaces based on the keyboard, mouse, trackballs, joysticks, and so forth. In particular, mobile devices have rapidly transitioned to adopt touch screen technologies as the primary means of user interface during recent years, enabling fun new interactive applications and experiences for the users. We have dedicated this special section of the Journal of the Society for Information Display to present an overview of recent developments and trends in the emerging field of interactive display technologies.     

A Study of Pointing Performance of Elderly Users on Smartphones

The number of global smartphone users is rapidly increasing. However, the proportion of elderly persons using smartphones is lower than that of other age groups because they feel it is difficult to use touch screens. There have only been a few studies about usability and elderly smartphone users or designs for them. Based on this background, we studied the pointing action of elderly users, which is a basic skill required to use touch screens on smartphones. We reviewed previous works to determine specific research methods and categorized them into three groups: (a) effect of target size and spacing on touch screen pointing performance, (b) effect of age on pointing performance, and (c) feedback of touch screens. To investigate the touch screen pointing performance of elderly, we conducted two experiments. In the first experiment, 3 target sizes (5 mm, 8 mm, and 12 mm) and 2 target spacings (1 mm, 3 mm) were evaluated. Adding to that, we analyzed whether touch screen pointing performance is dependent on the location of the target. In the second experiment, 3 types of feedback (auditory, tactile, and audiotactile) were evaluated. The results show that (a) pointing performance of elderly was significantly influenced by size, spacing, and location of target, and (b) the performance was higher in audiotactile feedback condition. We expected that these results can contribute to the design of smartphone applications for elderly users.